1. Field of the Invention
This invention generally relates to a video signal processing apparatus, and specifically relates to a video signal processing apparatus usable in a television opaque projector, a superimposing apparatus, or the like.
2. Description of the Prior Art
It is known to superimpose letters or pictures over images reproduced from video tape recorders (video tape reproducing devices) and television receivers. In some cases, the letters and still pictures to be superimposed are generated by computers. As a result, the superimposed letters or the still pictures tend to have jagged edges. This phenomenon is generally called "aliasing".
There are known anti-aliasing apparatuses which prevent jagged edges of superimposed letters and still pictures. The known anti-aliasing apparatuses are limited to be effective in the case of stationary background images but are generally ineffective in the case of moving background images such as video programs reproduced from a vido tape recorder.